Metrohm IC Net 2.2 - Manual (Page 157)

7.3 Method setup
IC Net 2.2 149
7.3.3 Filters
Tab Filters of Method setup window with parameters for noise filtra-
tion of raw data. Three different filtration algorithms are available
to reduce noise and increase apparent signal-to-noise ratio.
Spikes Spikes filter. The Spikes filter smoothes
the first and last points of the chroma-
togram and the points identified as spikes.
The spike is exchanged with half of the sum
of two neighboring signal values.
Slit Median Median filter. Performs filtration if non-zero
smoothing degree is entered. Smoothing
degree should be a natural number. The
values within the window are sorted by in-
creasing response level and the response
corresponding to the middle of the window
is replaced with the value in the middle of a
sorted array. This method affects chroma-
tographic peaks in minimal extent, im-
proves baseline and eliminates single-point
spikes. In this case the spike will be re-
placed with one of the neighboring points.
Slit Gaussian Gauss filter. Performs filtration if non-zero
smoothing degree is entered. The sum of
all window points with Gaussian weights
distribution is calculated and is used as a
new raw data value. The peaks become a
bit smaller and wider after smoothing, but
their area does not change.
Raw data points
Number of data points per chromatogram
(read-only).
Smallest peak has ...
Number of data points per smallest peak
on the chromatogram (read-only). This in-
formation is valuable to perform the
Com-
press procedure (data compression).